51茶馆

In 2016, at least 41 million children younger than 5 years worldwide were estimated to be obese or overweight. Data suggest this number is likely to increase to at least 50 million by 2030, with those affected coming primarily from low-income and middle-income demographics (World Health Organisation, 2016) and the likelihood of obesity continuing from childhood into adulthood.

In April 2019, following on from the release of the Early Years (0-5 years) guidelines in 2017, the Australian Minister for Sport, Senator the Hon. Bridget McKenzie and 51茶馆 (UOW) physical activity expert Professor Tony Okely launched the new .

Since their release the reports have attracted greater than 60 million media impressions worldwide. There is widespread interest in the recommendations with the general population keen to answer the question 鈥淗ow much daily physical activity, sedentary behaviour and sleep is associated with the best physical, social-emotional, cognitive and motor development outcomes for young children?鈥�

These Guidelines are based on the best available evidence, were developed by experts and stakeholders from across Australia and were designed to give parents and carers the best and current practical advice on healthy daily practices for children and adolescents.

They recommend children and young people participate in a range of physical activities, get good quality sleep, and limit screen time and prolonged sitting in order to optimise their physical and mental health, emotional regulation and social behaviour, and academic achievement and cognitive development.

Since previous Guidelines were released in 2012, the use and popularity of hand-held technologies such as phones and tablets and associated apps 鈥� especially ones targeting children and young people 鈥� have proliferated exponentially. With this in mind, the new Guidelines advised limiting sedentary recreational screen time, but they drew a distinction between recreational screen time and the use of electronic media for educational purposes.

The forces of technological change (both from a user experience perspective and a research analysis view point) are increasingly disrupting existing research findings and providing compelling paths to improved knowledge, a fact Early Start鈥檚 Dr Dylan Cliff (who was a member of the leadership group that developed the existing guidelines) is fully aware of.

鈥淭here are hundreds of studies that show that movement behaviours each influence child development. The problem is, just like a healthy meal will involve a mix of foods, a child鈥檚 day involves a mix of movement behaviours, and the daily mix is likely to influence their healthy development.鈥�

His team believe that movement behaviour data could be collected and analysed more effectively, to take into account this daily mix of activity. In previous studies sleep, sedentary behaviour and physical activity have been considered in isolation and investigated as separate behaviours. Cliff鈥檚 team believes this view could be problematic because in reality movement behaviours are not independent of each other. Rather they are co-dependent - when time in one behaviour is altered it must cause an equal and opposite change in time spent in one or more of the others across the 24-hour day.

鈥淔ollowing discussions with colleagues about the development of an international movement behaviour database and how this could inform the guidelines, I contacted Associate Professor Janette Green (from UOW鈥檚 Faculty of Business and ASHRI) who has expertise in health databases. Through funding from UOW's Global Challenges program we were able to hold a meeting in Hong Kong to bring together a team of international researchers to plan the SADEY project (the Sleep and Activity Database for the Early Years) and apply for funding through the Australian Research Council.鈥� Says Cliff

The ARC have provided three years of funding to develop the first comprehensive international database of young children鈥檚 movement behaviours by harmonising secondary data from at least 15 different studies. This will enable the analysis of data from over 14,000 participants, wearing the same objective wearable activity trackers.

Colleagues from the University of South Australia, Cambridge University in the UK and Queen's University and the Children鈥檚 Hospital at Eastern Ontario, Canada, as well as researchers from many parts of the world including Europe, Asia, South America and Africa will partner with UOW in developing the database. The sheer scale of this national and international collaboration makes this project impressive, with an expansion of possibilities, but it鈥檚 the technology of new data analysis tools and cross-pollination of research techniques from other sectors that make this project all the more exciting.

鈥淲e鈥檒l borrow analytical techniques called 鈥渃ompositional data analysis鈥� or CoDA from our colleagues in other fields. Developed more than 40 years ago and used in geology and other disciplines, but new to our field, CoDA will help us discover the best daily mix of movement behaviours for healthy child development. This approach will allow us to treat movement behaviour data as inter-related (i.e. a composition) and part of a finite whole 鈥� that is, despite our wishes, we cannot have more than 24 hours in a day! These analyses will also allow us to identify the optimal levels of each behaviour that result in the best developmental outcomes for children - the 鈥淕oldilocks zone鈥� where the balance of behaviours is 鈥渏ust right鈥� - which is important for informing guidelines related to these behaviours.鈥� Says Cliff.

鈥淏y bringing in additional database expertise to combine many datasets, plus the new-to-the-field statistical analysis techniques, this project will open research opportunities that wouldn鈥檛 be available otherwise. This is a great example of the combination being bigger than the sum of the parts.鈥� Says Associate Professor Janette Green who is often called on for her expert statistical skills on projects, primarily in classification development, benchmarking and outcome measurement.

鈥淪ADEY will be our baby for the next 3 years and beyond, and she鈥檒l put on weight rapidly in the first year of life as international researchers partner with us by contributing data.鈥�

In the meantime while data is collected, analysed and scrutinised, and the 鈥渕essage鈥� is crafted for an international and national audience, Cliff believes The Australian 24-hour movement behaviour guidelines for early years are the best place to start when considering young children鈥檚 healthy balance of physical activity, sleep and sitting time each day. He also advises to remember to revisit the guidelines when children cross developmental stages from infancy to the pre-school years and beyond.

• DR DYLAN CLIFF: To find out more about Dr Dylan Cliff take a look at his 
• ASSOCIATE PROFESSOR JANETTE GREEN: To find out more about Associate Professor Janette Green